Re: [Qemu-devel] [PATCH for-2.5??] configure: Fix shell syntax to placate OpenBSD's pdksh

[Eric Blake <eblake@redhat.com>]

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On 12/14/2015 08:02 AM, Peter Maydell wrote:
> Unfortunately the OpenBSD pdksh does not like brackets inside
> the right part of a ${variable+word} parameter expansion:
> 
>   $ echo "${a+($b)}"
>   ksh: ${a+($b)}": bad substitution
> 
> though both bash and dash accept them. In any case this line
> was causing odd output in the case where nettle is not present:
>   nettle    no ()
> 
> (because if nettle is not present then $nettle will be "no",
> not a null string or unset).
> 
> Rewrite it to just use an if.
> 
> This bug was originally introduced in becaeb726 and was present
> in the 2.4.0 release.
> 
> Fixes: https://bugs.launchpad.net/qemu/+bug/1525682
> Reported-by: Dmitrij D. Czarkoff
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
> This fixes a problem where configure just falls over on OpenBSD,
> but on the other hand it is not a regression since 2.4.0...
> Opinions on whether we should put it in 2.5 as a last minute
> thing welcome.

Can OpenBSD users do:

/path/to/bash ./configure

to work around it?

That, and the fact that we went an entire release cycle without a report
of a problem, means few developers are even attempting OpenBSD builds.
So, I would argue that as a non-regression, and where there is a likely
workaround of using a different shell, this can wait until 2.6.

> 
>  configure | 6 +++++-
>  1 file changed, 5 insertions(+), 1 deletion(-)
> 
> diff --git a/configure b/configure
> index b9552fd..6ca6c64 100755
> --- a/configure
> +++ b/configure
> @@ -4758,7 +4758,11 @@ echo "GTK GL support    $gtk_gl"
>  echo "GNUTLS support    $gnutls"
>  echo "GNUTLS hash       $gnutls_hash"
>  echo "libgcrypt         $gcrypt"
> -echo "nettle            $nettle ${nettle+($nettle_version)}"
> +if test "$nettle" = "yes"; then
> +    echo "nettle            $nettle ($nettle_version)"
> +else
> +    echo "nettle            $nettle"
> +fi

At any rate,
Reviewed-by: Eric Blake <eblake@redhat.com>

>  echo "libtasn1          $tasn1"
>  echo "VTE support       $vte"
>  echo "curses support    $curses"
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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